The Influence of Adaptive Co-management Interrelations on the Social Learning, Change and Transformation of the Pugu and Kazimzumbwi Community in Tanzania
- Authors: Ferdinand, Victoria
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387311 , vital:68224 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137668"
- Description: This study sought to identify signs of social learning, change and transformation resulting from adaptive co-management interrelations in terms of the project ‘Reduction of Emission from Deforestation and Forest Degradation’ (REDD) at the Pugu and Kazimzumbwi Forest Reserves (PKFR) community in Tanzania. The study therefore presents some enablers and constraints in respect of learning, agency formation, social change and transformation potentially influenced by the REDD. This is a qualitative case study that explored ‘learning’1 from living experiences of local people at the PKFR and from local mechanisms of the REDD project. Reflexive workshop interventions were used to validate the performance of local REDD practices against the adaptive co-management framework. Other data was obtained through interviews, focus-group discussion, the analysis of documents and direct observations. The study found that individual people may deepen their understanding of forestry issues through collaborative interrelations. Social learning in the PKFR community was potentially stimulated by people’s relational interactions, reflective thinking and anticipations, and questioning of past practices. Learning occurred subtly, and the learning process was not endured firmly enough to foster the complex learning dynamics necessary for transformational changes. As a result, most of the REDD-stimulated learning did not transform the practices desired in the project.
- Full Text:
- Authors: Ferdinand, Victoria
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387311 , vital:68224 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137668"
- Description: This study sought to identify signs of social learning, change and transformation resulting from adaptive co-management interrelations in terms of the project ‘Reduction of Emission from Deforestation and Forest Degradation’ (REDD) at the Pugu and Kazimzumbwi Forest Reserves (PKFR) community in Tanzania. The study therefore presents some enablers and constraints in respect of learning, agency formation, social change and transformation potentially influenced by the REDD. This is a qualitative case study that explored ‘learning’1 from living experiences of local people at the PKFR and from local mechanisms of the REDD project. Reflexive workshop interventions were used to validate the performance of local REDD practices against the adaptive co-management framework. Other data was obtained through interviews, focus-group discussion, the analysis of documents and direct observations. The study found that individual people may deepen their understanding of forestry issues through collaborative interrelations. Social learning in the PKFR community was potentially stimulated by people’s relational interactions, reflective thinking and anticipations, and questioning of past practices. Learning occurred subtly, and the learning process was not endured firmly enough to foster the complex learning dynamics necessary for transformational changes. As a result, most of the REDD-stimulated learning did not transform the practices desired in the project.
- Full Text:
The influence of livelihood dependency, local ecological knowledge and market proximity on the ecological impacts of harvesting non-timber forest products
- Steele, Melita Z, Shackleton, Charlie M, Shaanker, Ramanan U, Ganeshaiah, Kotiganahalli N, Radloff, Sarah E
- Authors: Steele, Melita Z , Shackleton, Charlie M , Shaanker, Ramanan U , Ganeshaiah, Kotiganahalli N , Radloff, Sarah E
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180908 , vital:43669 , xlink:href="https://doi.org/10.1016/j.forpol.2014.07.011"
- Description: It is well established that non-timber forest products make significant contributions to rural incomes throughout most of the developing world. NTFP use frequently raises concerns about the sustainability of, or ecological impacts associated with, NTFP harvesting, as well as local contextual factors which may limit or reduce the impacts. Here we test the conceptual model first advanced by Uma Shaanker et al. (2004) relating to the factors that may limit or exacerbate the ecological impacts associated with NTFP harvesting. These were the extent of local dependence on NTFPs, the degree of marketing and the level of local ecological knowledge. Data were collected via household questionnaires and ecological surveys of woody plants from eight villages throughout South Africa. We found no significant relationships between measures of ecological impact with local ecological knowledge or market proximity and engagement. There was a strong positive relationship between ecological impacts and NTFP dependency as indexed through mean annual direct-use value for NTFPs. This indicates that the higher the dependency and demand for NTFPs, the greater is the possibility of high impacts to the local environment. However, other contextual drivers not included in the original Uma Shaanker et al. (2004) model may also play a role, particularly the strength of local resource governance institutions.
- Full Text: false
- Authors: Steele, Melita Z , Shackleton, Charlie M , Shaanker, Ramanan U , Ganeshaiah, Kotiganahalli N , Radloff, Sarah E
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180908 , vital:43669 , xlink:href="https://doi.org/10.1016/j.forpol.2014.07.011"
- Description: It is well established that non-timber forest products make significant contributions to rural incomes throughout most of the developing world. NTFP use frequently raises concerns about the sustainability of, or ecological impacts associated with, NTFP harvesting, as well as local contextual factors which may limit or reduce the impacts. Here we test the conceptual model first advanced by Uma Shaanker et al. (2004) relating to the factors that may limit or exacerbate the ecological impacts associated with NTFP harvesting. These were the extent of local dependence on NTFPs, the degree of marketing and the level of local ecological knowledge. Data were collected via household questionnaires and ecological surveys of woody plants from eight villages throughout South Africa. We found no significant relationships between measures of ecological impact with local ecological knowledge or market proximity and engagement. There was a strong positive relationship between ecological impacts and NTFP dependency as indexed through mean annual direct-use value for NTFPs. This indicates that the higher the dependency and demand for NTFPs, the greater is the possibility of high impacts to the local environment. However, other contextual drivers not included in the original Uma Shaanker et al. (2004) model may also play a role, particularly the strength of local resource governance institutions.
- Full Text: false
The listening train: A collaborative, connective aesthetics approach to transgressive social learning
- Authors: McGarry, Dylan K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/371023 , vital:66404 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137658"
- Description: This paper explores a personal iterative retrospective of a series of expansive social-learning processes that were collaboratively developed through practice-based enquiry across 17 South African towns/contexts. This reflexive narrative explores the development of a ‘Climate Train’, a mobile social-learning platform, that was conceived and created through a collaborative social movement of ‘cultural practitioners’ ranging from visual artists, poets, film-makers, theatre-makers, guerrilla-gardeners, musicians, facilitators, to educational researchers, among others, who created new ‘connective aesthetic’ social spaces for dialogue and exchange. Drawing from a variety of artistic genres, including but not limited to theatre and social sculpture (an expanded concept of public/participatory art), I reflect on the formative, foundational qualities of these approaches and share insights into social-learning praxis that emerged on the tracks. Of primary focus is the use of aesthetic praxis as a means that transforms how we engage with our inner capacities as well as how we develop our relational sensibilities. Key findings include the vital role of connective aesthetics in establishing imaginal thinking, moral intuition, empathy, participative parity, and emergence, and how these are important for transformation and establishing new capacities for ecological/global citizenship and collaborative intelligence.
- Full Text:
- Authors: McGarry, Dylan K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/371023 , vital:66404 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137658"
- Description: This paper explores a personal iterative retrospective of a series of expansive social-learning processes that were collaboratively developed through practice-based enquiry across 17 South African towns/contexts. This reflexive narrative explores the development of a ‘Climate Train’, a mobile social-learning platform, that was conceived and created through a collaborative social movement of ‘cultural practitioners’ ranging from visual artists, poets, film-makers, theatre-makers, guerrilla-gardeners, musicians, facilitators, to educational researchers, among others, who created new ‘connective aesthetic’ social spaces for dialogue and exchange. Drawing from a variety of artistic genres, including but not limited to theatre and social sculpture (an expanded concept of public/participatory art), I reflect on the formative, foundational qualities of these approaches and share insights into social-learning praxis that emerged on the tracks. Of primary focus is the use of aesthetic praxis as a means that transforms how we engage with our inner capacities as well as how we develop our relational sensibilities. Key findings include the vital role of connective aesthetics in establishing imaginal thinking, moral intuition, empathy, participative parity, and emergence, and how these are important for transformation and establishing new capacities for ecological/global citizenship and collaborative intelligence.
- Full Text:
The nocturnal larvae of a specialist folivore perform better on C hromolaena odorata leaves from a shaded environment
- Osariyekemwen O. Uyi, Costas Zachariades, Hill, Martin P, Conlong, Desmond
- Authors: Osariyekemwen O. Uyi , Costas Zachariades , Hill, Martin P , Conlong, Desmond
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424855 , vital:72189 , xlink:href="https://doi.org/10.1111/eea.12321"
- Description: Increasing evidence suggests that individuals of the same plant species occurring in different micro-habitats often show a degree of phenotypic and phytochemical variation. Consequently, insect herbivores associated with such plant species must deal with environment-mediated changes or variability in the traits of their host plants. In this study, we examined the effects of habitat condition (shadedvs. full-sun habitats) on plant traits and leaf characteristics of the invasive alien plant, Chromolaenaodorata (L.) King and Robinson (Asteraceae). In addition, the performance was evaluated in two generations of a specialist folivore, Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae: Arctiinae), on leaves obtained from both shaded and full-sun habitats. The study was done in an area where the insect was introduced as a biological control agent. Leaves growing in shade were less tough, had higher water and nitrogen content, and lower total non-structural carbohydrate, compared with leaves growing in full sun. Plants growing in shade had longer leaves and were taller, but above-ground biomass was significantly reduced compared with plants growing in full sun. In both generations (parents and offspring), P. insulata developed faster and had larger pupal mass, increased growth rate, and higher fecundity when reared on shaded foliage compared with full-sun foliage. Although immature survival and adult longevity did not differ between habitats, Maw’s host suitability index indicated that shaded leaves were more suitable for the growth and reproduction of P. insulata. We suggest that the benefits obtained by P.insulata feeding on shaded foliage are associated with reduced toughness and enhanced nitrogen and water content of leaves. These results demonstrate that light-mediated changes in plant traits and leaf characteristics can affect insect folivore performance.
- Full Text:
- Authors: Osariyekemwen O. Uyi , Costas Zachariades , Hill, Martin P , Conlong, Desmond
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424855 , vital:72189 , xlink:href="https://doi.org/10.1111/eea.12321"
- Description: Increasing evidence suggests that individuals of the same plant species occurring in different micro-habitats often show a degree of phenotypic and phytochemical variation. Consequently, insect herbivores associated with such plant species must deal with environment-mediated changes or variability in the traits of their host plants. In this study, we examined the effects of habitat condition (shadedvs. full-sun habitats) on plant traits and leaf characteristics of the invasive alien plant, Chromolaenaodorata (L.) King and Robinson (Asteraceae). In addition, the performance was evaluated in two generations of a specialist folivore, Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae: Arctiinae), on leaves obtained from both shaded and full-sun habitats. The study was done in an area where the insect was introduced as a biological control agent. Leaves growing in shade were less tough, had higher water and nitrogen content, and lower total non-structural carbohydrate, compared with leaves growing in full sun. Plants growing in shade had longer leaves and were taller, but above-ground biomass was significantly reduced compared with plants growing in full sun. In both generations (parents and offspring), P. insulata developed faster and had larger pupal mass, increased growth rate, and higher fecundity when reared on shaded foliage compared with full-sun foliage. Although immature survival and adult longevity did not differ between habitats, Maw’s host suitability index indicated that shaded leaves were more suitable for the growth and reproduction of P. insulata. We suggest that the benefits obtained by P.insulata feeding on shaded foliage are associated with reduced toughness and enhanced nitrogen and water content of leaves. These results demonstrate that light-mediated changes in plant traits and leaf characteristics can affect insect folivore performance.
- Full Text:
The nonlinear absorption in new lanthanide double decker pyridine-based phthalocyanines in solution and thin films
- Sekhosana, Kutloana E, Nyokong, Tebello
- Authors: Sekhosana, Kutloana E , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189307 , vital:44836 , xlink:href="https://doi.org/10.1016/j.optmat.2015.05.022"
- Description: The optical behavior of bis-{2(3), 9(10), 16(17), 23(24)-(tetrapyridin-4-yloxy phthalocyaninato)} lanthanum (III) (2) and its ytterbium (3) counterpart in dimethyl sulfoxide are presented and compared to bis-{1(4), 8(11), 15(18), 22(25)-(tetrapyridin-4-yloxy phthalocyaninato)} ytterbium (III) (4). We report on the third-order susceptibility, second-order hyperpolarizability and the limiting threshold values. The nonlinear optical limiting threshold values of complexes 2, 3 and 4 showed improvement in the solid state (thin films), with complex 4 giving the best value at 0.033 J cm−2.
- Full Text:
- Authors: Sekhosana, Kutloana E , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189307 , vital:44836 , xlink:href="https://doi.org/10.1016/j.optmat.2015.05.022"
- Description: The optical behavior of bis-{2(3), 9(10), 16(17), 23(24)-(tetrapyridin-4-yloxy phthalocyaninato)} lanthanum (III) (2) and its ytterbium (3) counterpart in dimethyl sulfoxide are presented and compared to bis-{1(4), 8(11), 15(18), 22(25)-(tetrapyridin-4-yloxy phthalocyaninato)} ytterbium (III) (4). We report on the third-order susceptibility, second-order hyperpolarizability and the limiting threshold values. The nonlinear optical limiting threshold values of complexes 2, 3 and 4 showed improvement in the solid state (thin films), with complex 4 giving the best value at 0.033 J cm−2.
- Full Text:
The nursery role of a sheltered surf-zone in warm-temperate southern Africa
- Rishworth, Gavin M, Strydom, Nadine A, Potts, Warren M
- Authors: Rishworth, Gavin M , Strydom, Nadine A , Potts, Warren M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443651 , vital:74141 , https://hdl.handle.net/10520/EJC177697
- Description: Marine fish nurseries such as surf-zones have usually been classified as nurseries based solely on the density of pre-adult fish, yet the full suite of developmental stages are seldom assessed because of difficulties associated with sampling these habitats. The larval and early juvenile fish assemblage was studied in a sheltered surf-zone (King's Beach, South Africa), where high densities of older juveniles are known to occur. Fishes were collected fortnightly over six months using two modified seine nets. Although the surf composition included typical species for this habitat type, Gobiidae, Gobiesocidae and Haemulidae dominated the larval assemblage, which suggested that the nearby rocky structure and estuaries have an influence on the assemblage. Three species, Liza richardsonii (Mugilidae), Pomadasys olivaceus (Haemulidae) and Diplodus capensis (Sparidae), showed evidence of growth and recruitment into the surf-zone from the late larval stage. The high density of larval and juvenile fishes, the presence of more than one early life history stage and the observed growth of fishes suggests that King's Beach provides a suitable nursery habitat for several fishes.
- Full Text:
- Authors: Rishworth, Gavin M , Strydom, Nadine A , Potts, Warren M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443651 , vital:74141 , https://hdl.handle.net/10520/EJC177697
- Description: Marine fish nurseries such as surf-zones have usually been classified as nurseries based solely on the density of pre-adult fish, yet the full suite of developmental stages are seldom assessed because of difficulties associated with sampling these habitats. The larval and early juvenile fish assemblage was studied in a sheltered surf-zone (King's Beach, South Africa), where high densities of older juveniles are known to occur. Fishes were collected fortnightly over six months using two modified seine nets. Although the surf composition included typical species for this habitat type, Gobiidae, Gobiesocidae and Haemulidae dominated the larval assemblage, which suggested that the nearby rocky structure and estuaries have an influence on the assemblage. Three species, Liza richardsonii (Mugilidae), Pomadasys olivaceus (Haemulidae) and Diplodus capensis (Sparidae), showed evidence of growth and recruitment into the surf-zone from the late larval stage. The high density of larval and juvenile fishes, the presence of more than one early life history stage and the observed growth of fishes suggests that King's Beach provides a suitable nursery habitat for several fishes.
- Full Text:
The photophysical properties of multi-functional quantum dots-magnetic nanoparticles—indium octacarboxyphthalocyanine nanocomposite
- Tshangana, Charmaine, Nyokong, Tebello
- Authors: Tshangana, Charmaine , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189876 , vital:44942 , xlink:href="https://doi.org/10.1007/s10895-014-1497-6"
- Description: This work presents the development of a multifunctional hybrid nanoparticle made of L-glutathione capped quantum dots (GSH-CdSe@ZnS), amino functionalized Fe3O4 magnetic nanoparticles and indium octacarboxy phthalocyanine (ClInPc(COOH)8). In this work we investigate the photophysical properties of the individual components and the hybrid nanoparticle, in addition we study the energy transfer (Förster Resonance Energy Transfer (FRET)) in the complex. FRET efficiencies of ~48 % were obtained for energy transfer between the QDs (when alone or linked to MNPs). Both triplet yields and lifetimes of ClInPc(COOH)8 increase in the nanocomposite, with a decrease in fluorescence lifetime. The hybrid nanoparticle showed improved photophysical properties and as a result can be used in photodynamic therapy.
- Full Text:
- Authors: Tshangana, Charmaine , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189876 , vital:44942 , xlink:href="https://doi.org/10.1007/s10895-014-1497-6"
- Description: This work presents the development of a multifunctional hybrid nanoparticle made of L-glutathione capped quantum dots (GSH-CdSe@ZnS), amino functionalized Fe3O4 magnetic nanoparticles and indium octacarboxy phthalocyanine (ClInPc(COOH)8). In this work we investigate the photophysical properties of the individual components and the hybrid nanoparticle, in addition we study the energy transfer (Förster Resonance Energy Transfer (FRET)) in the complex. FRET efficiencies of ~48 % were obtained for energy transfer between the QDs (when alone or linked to MNPs). Both triplet yields and lifetimes of ClInPc(COOH)8 increase in the nanocomposite, with a decrease in fluorescence lifetime. The hybrid nanoparticle showed improved photophysical properties and as a result can be used in photodynamic therapy.
- Full Text:
The politics of interweaving performance cultures
- Authors: Krueger, Anton
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/225719 , vital:49252 , xlink:href="https://doi.org/10.1080/10137548.2015.1014170"
- Description: According to the former president of the International Federation of Theatre Research (IFTR), Brian Singleton, the study of ‘[i]nterculturalism as a practice and a theory gained currency with Richard Schechner’s anthropologically-inspired new discipline of performance studies’ (p. 79). Schechner’s new discipline led to the formation of the annual Performance Studies International (PSI) conferences, and earlier this year I attended the twentieth instalment in Shanghai, which was held under the rubric of ‘Tradition and the Avant-Garde’. One of the things which struck me was the extent to which the (relatively) newly economically empowered Chinese theatre makers were creating grand productions based on Western theatre traditions. For example, many of the presentations for delegates were based on Western texts (such as Hamlet, Miss Julie and even a play by Woody Allen). And yet these productions were performed in Mandarin, using purist Chinese forms, such as Beijing Opera. During the discussions there seemed to be an awkward defensiveness from some of the Chinese hosts who insisted they were not ‘copying’ Western theatre, but that they were using it to express a pure Chinese aesthetic. There were also other performances at the conference, such as a series of parables called Confucius Disciples, which told didactic tales with content very foreign to a Western audience. A visiting troupe from Bulgaria presented their own version of some of these parables, using a strongly East European aesthetic to convey a Chinese message. In this way, experiments with cultural forms and content were clearly foregrounded by the conference presentations.
- Full Text:
- Authors: Krueger, Anton
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/225719 , vital:49252 , xlink:href="https://doi.org/10.1080/10137548.2015.1014170"
- Description: According to the former president of the International Federation of Theatre Research (IFTR), Brian Singleton, the study of ‘[i]nterculturalism as a practice and a theory gained currency with Richard Schechner’s anthropologically-inspired new discipline of performance studies’ (p. 79). Schechner’s new discipline led to the formation of the annual Performance Studies International (PSI) conferences, and earlier this year I attended the twentieth instalment in Shanghai, which was held under the rubric of ‘Tradition and the Avant-Garde’. One of the things which struck me was the extent to which the (relatively) newly economically empowered Chinese theatre makers were creating grand productions based on Western theatre traditions. For example, many of the presentations for delegates were based on Western texts (such as Hamlet, Miss Julie and even a play by Woody Allen). And yet these productions were performed in Mandarin, using purist Chinese forms, such as Beijing Opera. During the discussions there seemed to be an awkward defensiveness from some of the Chinese hosts who insisted they were not ‘copying’ Western theatre, but that they were using it to express a pure Chinese aesthetic. There were also other performances at the conference, such as a series of parables called Confucius Disciples, which told didactic tales with content very foreign to a Western audience. A visiting troupe from Bulgaria presented their own version of some of these parables, using a strongly East European aesthetic to convey a Chinese message. In this way, experiments with cultural forms and content were clearly foregrounded by the conference presentations.
- Full Text:
The politics of philosophy in Africa
- Jones, Ward E, Metz, Thaddeus
- Authors: Jones, Ward E , Metz, Thaddeus
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275733 , vital:55074 , xlink:href="https://doi.org/10.1080/02580136.2015.1104797"
- Description: The background to the present discussion is the prevalence of political and personal criticisms in philosophical discussions about Africa. As philosophers in South Africa—both white and black—continue to philosophise seriously about Africa, responses to their work sometimes take the form of political and personal criticisms of, if not attacks on, the philosopher exploring and defending considerations about the African continent. One of us (TM) has been the target of such critiques in light of his work. Our aim in this conversation is not to diminish or deflect such critiques. On the contrary, our aim is to understand them, to make them as strong as possible, and to bring them into the cooler realm of philosophical discussion.
- Full Text:
- Authors: Jones, Ward E , Metz, Thaddeus
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275733 , vital:55074 , xlink:href="https://doi.org/10.1080/02580136.2015.1104797"
- Description: The background to the present discussion is the prevalence of political and personal criticisms in philosophical discussions about Africa. As philosophers in South Africa—both white and black—continue to philosophise seriously about Africa, responses to their work sometimes take the form of political and personal criticisms of, if not attacks on, the philosopher exploring and defending considerations about the African continent. One of us (TM) has been the target of such critiques in light of his work. Our aim in this conversation is not to diminish or deflect such critiques. On the contrary, our aim is to understand them, to make them as strong as possible, and to bring them into the cooler realm of philosophical discussion.
- Full Text:
The prevalence of planning and management frameworks for trees and green spaces in urban areas of South Africa
- Chishaleshale, M, Shackleton, Charlie M, Gambiza, James, Gumbo, Davison
- Authors: Chishaleshale, M , Shackleton, Charlie M , Gambiza, James , Gumbo, Davison
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180884 , vital:43659 , xlink:href="https://doi.org/10.1016/j.ufug.2015.09.012"
- Description: Optimisation of the benefits from urban forestry and greening to urban dwellers and the environment rests on proactive and appropriate management planning, implementation and resourcing. Yet, lessons from the developed world show marked variability in development and adoption of urban tree and green space (UTGS) strategic plans and systematic monitoring and maintenance. Although financial and human resources for UTGS may be constrained in developing world contexts, there is no knowledge of the extent to which local authorities engage in appropriate and timely planning, management and monitoring. Here we examine the UTGS resourcing, planning, maintenance and integration across 28 local municipalities in the two poorest provinces in South Africa. It was revealed that most local municipalities were not managing their UTGS in a planned or systematic manner due to constraining factors such as insufficient funds, insufficient personnel, lack of equipment and lack of political support. Only 7% of the surveyed municipalities had an urban tree management plan and an estimate of the urban tree stock; 32% had tree policies; 21% had tree planting schedules; 11% had tree maintenance schedules. Over 65% claimed to engage other stakeholders in tree planting, but much was passive receipt of trees for planting rather than citizen engagement around species, places and values. Generally, the prevalence of most planning and maintenance elements increased with increasing size of the municipality and the presence of personnel specifically for UTGS management. It is likely that the prevalence of planning and maintenance functions will increase with greater political support from municipal councillors which may also decrease funding challenges.
- Full Text:
- Authors: Chishaleshale, M , Shackleton, Charlie M , Gambiza, James , Gumbo, Davison
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180884 , vital:43659 , xlink:href="https://doi.org/10.1016/j.ufug.2015.09.012"
- Description: Optimisation of the benefits from urban forestry and greening to urban dwellers and the environment rests on proactive and appropriate management planning, implementation and resourcing. Yet, lessons from the developed world show marked variability in development and adoption of urban tree and green space (UTGS) strategic plans and systematic monitoring and maintenance. Although financial and human resources for UTGS may be constrained in developing world contexts, there is no knowledge of the extent to which local authorities engage in appropriate and timely planning, management and monitoring. Here we examine the UTGS resourcing, planning, maintenance and integration across 28 local municipalities in the two poorest provinces in South Africa. It was revealed that most local municipalities were not managing their UTGS in a planned or systematic manner due to constraining factors such as insufficient funds, insufficient personnel, lack of equipment and lack of political support. Only 7% of the surveyed municipalities had an urban tree management plan and an estimate of the urban tree stock; 32% had tree policies; 21% had tree planting schedules; 11% had tree maintenance schedules. Over 65% claimed to engage other stakeholders in tree planting, but much was passive receipt of trees for planting rather than citizen engagement around species, places and values. Generally, the prevalence of most planning and maintenance elements increased with increasing size of the municipality and the presence of personnel specifically for UTGS management. It is likely that the prevalence of planning and maintenance functions will increase with greater political support from municipal councillors which may also decrease funding challenges.
- Full Text:
The subspecies of Antarctic Terns (Sterna vittata) wintering on the South African coast: evidence from morphology, genetics and stable isotopes
- Connan, Maëlle, Teske, Peter R, Tree, Anthony J, Whittington, Philip A, McQuaid, Christopher D
- Authors: Connan, Maëlle , Teske, Peter R , Tree, Anthony J , Whittington, Philip A , McQuaid, Christopher D
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444854 , vital:74303 , https://doi.org/10.1071/MU14089
- Description: Five to seven subspecies of Antarctic Tern (Sterna vittata) are recognised, with at least three (S. v. vittata, S. v. tristanensis and S. v. sanctipauli) wintering in South Africa. Morphological characters used to define these subspecies are not perfectly reliable, but fidelity to nesting site suggests they could be genetically distinct. We used morphological data and DNA to investigate the validity of subspecies. We further used stable isotope analysis of feather samples collected from the non-breeding grounds in South Africa to attempt to ascertain the population of origin. Nuclear and mitochondrial DNA sequence data identified two major genetic clades: one mostly comprised individuals partially or completely matching the morphological description of S. v. tristanensis, the other included individuals from S. v. vittata and S. v. sanctipauli. Stable isotope values indicated that juveniles originated from at least three populations. Irrespective of their morphological and genetic characteristics, most immatures moulted in Antarctic waters, and adults moulted in various habitats. Their colony of origin could not therefore be inferred from stable isotope values from feathers. Results indicate that morphological groupings may reflect a north-south cline across the Indian Ocean. Adequate conservation strategies require rigorous reassessment of the currently accepted subspecies, including DNA analyses of samples from the breeding grounds, particularly on Amsterdam and St Paul Islands.
- Full Text:
- Authors: Connan, Maëlle , Teske, Peter R , Tree, Anthony J , Whittington, Philip A , McQuaid, Christopher D
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444854 , vital:74303 , https://doi.org/10.1071/MU14089
- Description: Five to seven subspecies of Antarctic Tern (Sterna vittata) are recognised, with at least three (S. v. vittata, S. v. tristanensis and S. v. sanctipauli) wintering in South Africa. Morphological characters used to define these subspecies are not perfectly reliable, but fidelity to nesting site suggests they could be genetically distinct. We used morphological data and DNA to investigate the validity of subspecies. We further used stable isotope analysis of feather samples collected from the non-breeding grounds in South Africa to attempt to ascertain the population of origin. Nuclear and mitochondrial DNA sequence data identified two major genetic clades: one mostly comprised individuals partially or completely matching the morphological description of S. v. tristanensis, the other included individuals from S. v. vittata and S. v. sanctipauli. Stable isotope values indicated that juveniles originated from at least three populations. Irrespective of their morphological and genetic characteristics, most immatures moulted in Antarctic waters, and adults moulted in various habitats. Their colony of origin could not therefore be inferred from stable isotope values from feathers. Results indicate that morphological groupings may reflect a north-south cline across the Indian Ocean. Adequate conservation strategies require rigorous reassessment of the currently accepted subspecies, including DNA analyses of samples from the breeding grounds, particularly on Amsterdam and St Paul Islands.
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The timing of moult in males and females of the monomorphic Pale-winged Starling Onychognathus nabouroup
- Craig, Adrian J F K, Bonnevie, Bo T, Hausberger, Martine, Henry, Laurence
- Authors: Craig, Adrian J F K , Bonnevie, Bo T , Hausberger, Martine , Henry, Laurence
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443805 , vital:74155 , https://hdl.handle.net/10520/EJC177689
- Description: Pale-winged Starlings Onychognathus nabouroup inhabit the arid western interior of southern Africa and moult-breeding overlap may occur. We collected field data in two successive years on the moult of individual birds, whose sex was confirmed by genetic techniques. Small samples revealed a non-significant tendency for the moult of females in the early stages of wing moult to be more advanced than that of males in both years, but also clear evidence that the starting date of moult differed in the two years. In this species the moult schedule may thus be variable at both the individual and the population levels.
- Full Text:
- Authors: Craig, Adrian J F K , Bonnevie, Bo T , Hausberger, Martine , Henry, Laurence
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443805 , vital:74155 , https://hdl.handle.net/10520/EJC177689
- Description: Pale-winged Starlings Onychognathus nabouroup inhabit the arid western interior of southern Africa and moult-breeding overlap may occur. We collected field data in two successive years on the moult of individual birds, whose sex was confirmed by genetic techniques. Small samples revealed a non-significant tendency for the moult of females in the early stages of wing moult to be more advanced than that of males in both years, but also clear evidence that the starting date of moult differed in the two years. In this species the moult schedule may thus be variable at both the individual and the population levels.
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The trade in and household use of Phoenix reclinata palm frond hand brushes on the Wild Coast, South Africa: Effects on soil nutrients
- Mjoli, Nwabisa, Shackleton, Charlie M
- Authors: Mjoli, Nwabisa , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180800 , vital:43647 , xlink:href="https://doi.org/10.1007/s12231-015-9316-9"
- Description: The Trade in and Household Use of Phoenix reclinata Palm Frond Hand Brushes on the Wild Coast, South Africa. This paper reports on an investigation of the harvesting, trade, and use of hand brushes made from fronds of the wild palm, Phoenix reclinata. We considered both the abundance of the resource as well as the demand. Within the harvesting areas, there were approximately 141 palm plants per hectare, of which almost two-thirds showed no signs of frond harvesting. During harvesting, most fronds (82%) were left on the plant, 16% were removed to make brushes, and 2% were cut and discarded. Although the number of harvesters had increased during the last decade, most felt that the number of palm plants had remained stable or even increased over the same period. There was strong consensus that cut fronds were replaced within two months, after which a particular stem could be harvested again. Harvesting and trade were practiced largely by middle-aged to elderly women, who had limited formal education, skills, and employment prospects. Most had entered the trade because of cash income poverty. The main markets for selling the palm brushes were in nearby urban areas. The income earned from the trade was modest, but still rated highly by the traders, for most of whom it was the second most-important source of cash income. For many users, the palm brushes was found to be the only type of brush suitable for cleaning mud and cow-dung flooring and, most importantly for many, their use forms part of a long household use history and culture.
- Full Text:
- Authors: Mjoli, Nwabisa , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180800 , vital:43647 , xlink:href="https://doi.org/10.1007/s12231-015-9316-9"
- Description: The Trade in and Household Use of Phoenix reclinata Palm Frond Hand Brushes on the Wild Coast, South Africa. This paper reports on an investigation of the harvesting, trade, and use of hand brushes made from fronds of the wild palm, Phoenix reclinata. We considered both the abundance of the resource as well as the demand. Within the harvesting areas, there were approximately 141 palm plants per hectare, of which almost two-thirds showed no signs of frond harvesting. During harvesting, most fronds (82%) were left on the plant, 16% were removed to make brushes, and 2% were cut and discarded. Although the number of harvesters had increased during the last decade, most felt that the number of palm plants had remained stable or even increased over the same period. There was strong consensus that cut fronds were replaced within two months, after which a particular stem could be harvested again. Harvesting and trade were practiced largely by middle-aged to elderly women, who had limited formal education, skills, and employment prospects. Most had entered the trade because of cash income poverty. The main markets for selling the palm brushes were in nearby urban areas. The income earned from the trade was modest, but still rated highly by the traders, for most of whom it was the second most-important source of cash income. For many users, the palm brushes was found to be the only type of brush suitable for cleaning mud and cow-dung flooring and, most importantly for many, their use forms part of a long household use history and culture.
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The women of Willowvale-crafting livelihoods from the wild date palm
- Mjoli, Nwabisa, Shackleton, Charlie M
- Authors: Mjoli, Nwabisa , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182322 , vital:43820 , xlink:href="https://hdl.handle.net/10520/EJC185235"
- Description: The Wild Coast of the Eastern Cape is renowned for its cultural landscapes, stunning scenery and remarkable biodiversity. It is also one of the least developed regions of South Africa, which underpins the small productive base and limited economic opportunities for the hundreds of rural communities scattered along the hilltops. It is not surprising therefore, that many inhabitants make extensive use of natural resources, such as firewood, reed mats, medicinal plants and wild vegetables, in their daily lives, as well as for sources of income when the opportunity arises.
- Full Text:
- Authors: Mjoli, Nwabisa , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182322 , vital:43820 , xlink:href="https://hdl.handle.net/10520/EJC185235"
- Description: The Wild Coast of the Eastern Cape is renowned for its cultural landscapes, stunning scenery and remarkable biodiversity. It is also one of the least developed regions of South Africa, which underpins the small productive base and limited economic opportunities for the hundreds of rural communities scattered along the hilltops. It is not surprising therefore, that many inhabitants make extensive use of natural resources, such as firewood, reed mats, medicinal plants and wild vegetables, in their daily lives, as well as for sources of income when the opportunity arises.
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Towards a PHP webshell taxonomy using deobfuscation-assisted similarity analysis
- Wrench, Peter M, Irwin, Barry V W
- Authors: Wrench, Peter M , Irwin, Barry V W
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429560 , vital:72622 , 10.1109/ISSA.2015.7335066
- Description: The abundance of PHP-based Remote Access Trojans (or web shells) found in the wild has led malware researchers to develop systems capable of tracking and analysing these shells. In the past, such shells were ably classified using signature matching, a process that is currently unable to cope with the sheer volume and variety of web-based malware in circulation. Although a large percentage of newly-created webshell software incorporates portions of code derived from seminal shells such as c99 and r57, they are able to disguise this by making extensive use of obfuscation techniques intended to frustrate any attempts to dissect or reverse engineer the code. This paper presents an approach to shell classification and analysis (based on similarity to a body of known malware) in an attempt to create a comprehensive taxonomy of PHP-based web shells. Several different measures of similarity were used in conjunction with clustering algorithms and visualisation techniques in order to achieve this. Furthermore, an auxiliary component capable of syntactically deobfuscating PHP code is described. This was employed to reverse idiomatic obfuscation constructs used by software authors. It was found that this deobfuscation dramatically increased the observed levels of similarity by exposing additional code for analysis.
- Full Text:
- Authors: Wrench, Peter M , Irwin, Barry V W
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429560 , vital:72622 , 10.1109/ISSA.2015.7335066
- Description: The abundance of PHP-based Remote Access Trojans (or web shells) found in the wild has led malware researchers to develop systems capable of tracking and analysing these shells. In the past, such shells were ably classified using signature matching, a process that is currently unable to cope with the sheer volume and variety of web-based malware in circulation. Although a large percentage of newly-created webshell software incorporates portions of code derived from seminal shells such as c99 and r57, they are able to disguise this by making extensive use of obfuscation techniques intended to frustrate any attempts to dissect or reverse engineer the code. This paper presents an approach to shell classification and analysis (based on similarity to a body of known malware) in an attempt to create a comprehensive taxonomy of PHP-based web shells. Several different measures of similarity were used in conjunction with clustering algorithms and visualisation techniques in order to achieve this. Furthermore, an auxiliary component capable of syntactically deobfuscating PHP code is described. This was employed to reverse idiomatic obfuscation constructs used by software authors. It was found that this deobfuscation dramatically increased the observed levels of similarity by exposing additional code for analysis.
- Full Text:
Towards assessing impacts of alien plant infestations on river systems in the Southern Cape using cost-benefit analyses
- Rivers-Moore, Nick A, Dallas, Helen F, Barendse, Jaco, de Moor, Ferdy C
- Authors: Rivers-Moore, Nick A , Dallas, Helen F , Barendse, Jaco , de Moor, Ferdy C
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438336 , vital:73452 , ISBN 978-1-4312-0661-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2264.pdf
- Description: Ecosystem resilience is key to the provision of dependable ecosystem goods and services, and it is generally accepted that ecosystem diversity helps to maintain sys-tem resilience. It is therefore reasonable to postulate that changes to the variables that drive species patterns will result in changes to ecosystem community structure and consequently negatively impact on system resilience. Alien vegetation in the riparian zone can impact on water temperatures, flow patterns, degree of shading, channel modification, and changes to natural sediment loads. Climate change is likely to exacerbate the problem both directly through its amplification of thermal extremes in aquatic systems, and indirectly through its impacts on dispersal patterns of alien invasive vegetation.
- Full Text:
- Authors: Rivers-Moore, Nick A , Dallas, Helen F , Barendse, Jaco , de Moor, Ferdy C
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438336 , vital:73452 , ISBN 978-1-4312-0661-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/2264.pdf
- Description: Ecosystem resilience is key to the provision of dependable ecosystem goods and services, and it is generally accepted that ecosystem diversity helps to maintain sys-tem resilience. It is therefore reasonable to postulate that changes to the variables that drive species patterns will result in changes to ecosystem community structure and consequently negatively impact on system resilience. Alien vegetation in the riparian zone can impact on water temperatures, flow patterns, degree of shading, channel modification, and changes to natural sediment loads. Climate change is likely to exacerbate the problem both directly through its amplification of thermal extremes in aquatic systems, and indirectly through its impacts on dispersal patterns of alien invasive vegetation.
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Transformative processes in environmental education: A case study
- Fox, Helen, Palmer, Carolyn G, O'Donoghue, Rob B
- Authors: Fox, Helen , Palmer, Carolyn G , O'Donoghue, Rob B
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387323 , vital:68225 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137680"
- Description: This paper presents a case study on the severely degraded Boksburg Lake’s (Gauteng, South Africa) social–ecological system, and on an environmental-education initiative that aimed to support the lake’s transformation with a view to its improved social and ecological well-being. In this case study, three key characteristics of the initiative which appeared to support the transformative process are discussed, namely: 1. Learning was aligned with the local social–ecological context; 2. Human-to-human and human-to-ecological connections were encouraged; and 3. The youth played a key role in initiating and effecting transformation.
- Full Text:
- Authors: Fox, Helen , Palmer, Carolyn G , O'Donoghue, Rob B
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387323 , vital:68225 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137680"
- Description: This paper presents a case study on the severely degraded Boksburg Lake’s (Gauteng, South Africa) social–ecological system, and on an environmental-education initiative that aimed to support the lake’s transformation with a view to its improved social and ecological well-being. In this case study, three key characteristics of the initiative which appeared to support the transformative process are discussed, namely: 1. Learning was aligned with the local social–ecological context; 2. Human-to-human and human-to-ecological connections were encouraged; and 3. The youth played a key role in initiating and effecting transformation.
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Transformative, transgressive social learning: Rethinking higher education pedagogy in times of systemic global dysfunction
- Lotz-Sisitka, Heila, Wals, Arjen E J, Kronlid, David O, McGarry, Dylan K
- Authors: Lotz-Sisitka, Heila , Wals, Arjen E J , Kronlid, David O , McGarry, Dylan K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372794 , vital:66623 , xlink:href="https://doi.org/10.1016/j.cosust.2015.07.018"
- Description: The nature of the sustainability challenges currently at hand is such that dominant pedagogies and forms of learning that characterize higher education need to be reconsidered to enable students and staff to deal with accelerating change, increasing complexity, contested knowledge claims and inevitable uncertainty. In this contribution we identified four streams of emerging transformative, transgressive learning research and praxis in the sustainability sciences that appear generative of a higher education pedagogy that appears more responsive to the key challenges of our time: (1) reflexive social learning and capabilities theory, (2) critical phenomenology, (3) socio-cultural and cultural historical activity theory, and (4) new social movement, postcolonial and decolonisation theory. The paper critiques the current tendency in sustainability science and learning to rely on resilience and adaptive capacity building and argues that in order to break with maladaptive resilience of unsustainable systems it is essential to strengthen transgressive learning and disruptive capacity-building.
- Full Text:
- Authors: Lotz-Sisitka, Heila , Wals, Arjen E J , Kronlid, David O , McGarry, Dylan K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372794 , vital:66623 , xlink:href="https://doi.org/10.1016/j.cosust.2015.07.018"
- Description: The nature of the sustainability challenges currently at hand is such that dominant pedagogies and forms of learning that characterize higher education need to be reconsidered to enable students and staff to deal with accelerating change, increasing complexity, contested knowledge claims and inevitable uncertainty. In this contribution we identified four streams of emerging transformative, transgressive learning research and praxis in the sustainability sciences that appear generative of a higher education pedagogy that appears more responsive to the key challenges of our time: (1) reflexive social learning and capabilities theory, (2) critical phenomenology, (3) socio-cultural and cultural historical activity theory, and (4) new social movement, postcolonial and decolonisation theory. The paper critiques the current tendency in sustainability science and learning to rely on resilience and adaptive capacity building and argues that in order to break with maladaptive resilience of unsustainable systems it is essential to strengthen transgressive learning and disruptive capacity-building.
- Full Text:
Transformative, transgressive social learning: Rethinking higher education pedagogy in times of systemic global dysfunction
- Lotz-Sisitka, Heila, Wals, Arjen E, Kronlid, David O, McGarry, Dylan K
- Authors: Lotz-Sisitka, Heila , Wals, Arjen E , Kronlid, David O , McGarry, Dylan K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392190 , vital:68729 , xlink:href="https://doi.org/10.1016/j.cosust.2015.07.018"
- Description: The nature of the sustainability challenges currently at hand is such that dominant pedagogies and forms of learning that characterize higher education need to be reconsidered to enable students and staff to deal with accelerating change, increasing complexity, contested knowledge claims and inevitable uncertainty. In this contribution we identified four streams of emerging transformative, transgressive learning research and praxis in the sustainability sciences that appear generative of a higher education pedagogy that appears more responsive to the key challenges of our time: (1) reflexive social learning and capabilities theory, (2) critical phenomenology, (3) socio-cultural and cultural historical activity theory, and (4) new social movement, postcolonial and decolonisation theory. The paper critiques the current tendency in sustainability science and learning to rely on resilience and adaptive capacity building and argues that in order to break with maladaptive resilience of unsustainable systems it is essential to strengthen transgressive learning and disruptive capacity-building.
- Full Text:
- Authors: Lotz-Sisitka, Heila , Wals, Arjen E , Kronlid, David O , McGarry, Dylan K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/392190 , vital:68729 , xlink:href="https://doi.org/10.1016/j.cosust.2015.07.018"
- Description: The nature of the sustainability challenges currently at hand is such that dominant pedagogies and forms of learning that characterize higher education need to be reconsidered to enable students and staff to deal with accelerating change, increasing complexity, contested knowledge claims and inevitable uncertainty. In this contribution we identified four streams of emerging transformative, transgressive learning research and praxis in the sustainability sciences that appear generative of a higher education pedagogy that appears more responsive to the key challenges of our time: (1) reflexive social learning and capabilities theory, (2) critical phenomenology, (3) socio-cultural and cultural historical activity theory, and (4) new social movement, postcolonial and decolonisation theory. The paper critiques the current tendency in sustainability science and learning to rely on resilience and adaptive capacity building and argues that in order to break with maladaptive resilience of unsustainable systems it is essential to strengthen transgressive learning and disruptive capacity-building.
- Full Text:
Trophic relationships of hake (Merluccius capensis and M. paradoxus) and sharks (Centrophorus squamosus, Deania calcea and D. profundorum) in the Northern (Namibia) Benguela Current region
- Iitembu, Johannes A, Richoux, Nicole B
- Authors: Iitembu, Johannes A , Richoux, Nicole B
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443830 , vital:74157 , https://hdl.handle.net/10520/EJC183122
- Description: The trophic relationships of two hake species (Merluccius capensis and M. paradoxus) and three shark species (Centrophorus squamosus, Deania calcea and D. profundorum) were investigated using nitrogen and carbon stable isotope signatures (15N and 13C) of their muscle tissues. The sharks were more enriched in 15N than the hake, an indication of the apex predator status of sharks. Among the sharks considered, C. squamosus occupied the highest trophic level and fed primarily on benthic prey. The two species of shark from the genus Deania were not different based on 15N or 13C, so they had similar diets. The 13C signatures indicated that M. capensis and sharks fed on prey derived from similar basal resources. However, there was a significant difference in 13C between M. paradoxus and all other species examined, suggesting that they occupied different feeding niches. Isotope-based populationmetrics showed narrower trophic ranges in sharks than M. capensis. Carbon and nitrogen ranges indicated that hake fed on a more diverse pool of carbon sources and had generally more enhanced trophic diversity in their feeding patterns than sharks. Among the species considered, C. squamosus occupied a unique isotopic space. Our results supported the hypothesis there are trophic overlaps among these species, but some interesting differentiation was revealed.
- Full Text:
- Authors: Iitembu, Johannes A , Richoux, Nicole B
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443830 , vital:74157 , https://hdl.handle.net/10520/EJC183122
- Description: The trophic relationships of two hake species (Merluccius capensis and M. paradoxus) and three shark species (Centrophorus squamosus, Deania calcea and D. profundorum) were investigated using nitrogen and carbon stable isotope signatures (15N and 13C) of their muscle tissues. The sharks were more enriched in 15N than the hake, an indication of the apex predator status of sharks. Among the sharks considered, C. squamosus occupied the highest trophic level and fed primarily on benthic prey. The two species of shark from the genus Deania were not different based on 15N or 13C, so they had similar diets. The 13C signatures indicated that M. capensis and sharks fed on prey derived from similar basal resources. However, there was a significant difference in 13C between M. paradoxus and all other species examined, suggesting that they occupied different feeding niches. Isotope-based populationmetrics showed narrower trophic ranges in sharks than M. capensis. Carbon and nitrogen ranges indicated that hake fed on a more diverse pool of carbon sources and had generally more enhanced trophic diversity in their feeding patterns than sharks. Among the species considered, C. squamosus occupied a unique isotopic space. Our results supported the hypothesis there are trophic overlaps among these species, but some interesting differentiation was revealed.
- Full Text: